More on 300E Diff & Subframe mounts?
 

I have searched all the info about repairing my rear suspension, I am wondering if anyone has had the "definative experience" conccerning all things in the back. 1) Should I stop fooling myself and replace ALL that could go wrong? 2) Does anyone have the "ultimate subframe bushing removal" hints? 2) Same for the Diff mounts? 3) What is the best way to relieve the rear springs? Removing the inner bolts and lowering or the outer? Any updated experiences would be great! Thanks Scott PS I found all this stuff after looking under my car while starting the Ft. Brakes! I am never gonn alook under there again.....

And.......
 

Are the subframe mounts specific to VIN & Right or left side?

China,
 

Unless you have appropiate the tools, it is going to be difficult to replace the sub-frame bushings yourself. Let the professionals do it. The links are a different story...You can "relieve" the rear springs by removing the outer bolts with a jack under it. Be very careful! :eek:

My mechanic no longer does diff mounts or rear subframe mounts -- he works by himself, and he's semi-retired -- claims doing either job makes it almost impossible to work the next day!

Diff mounts are best removed with an air chisel, they almost never pull out of the subframe with a puller. Don't know about subframe mounts, but they look to be a serious pain, too.

I know what you mean about looking -- I've got to find out why I have serious torque steer on the 87 300D -- an expecting at least one link to be bad, am hoping it isn't bushings.

Peter

China Clipper,

1. Replacing everything can take your car out of commission a while especially if you find that you don't have the tools you need or aren't comfortable fabricating your own. If you rebuilt everything in the rear & leave the front alone, looseness in the front may be more evident - when everything is loose, it all tends to "blend" together...

2. The subframe bushings are NO big deal. I have done them, twice in fact (on two different subframes). For the first subframe, I did one side at a time with the subframe in the car. For the second subframe, I removed the entire subframe from the car. No because I had to, because I felt like it. The bushings CAN be removed without special tools. I busted the seals on my floor jack in the process. Installation can probably be done too.

3. There is NO reason to relieve pressure on the springs if you are doing subframe mounts. Only if you are replacing the support joint in the bottom of the wheel carrier. Or, you are replacing the lower control arm or the spring/spring pads. There is very little pressure on them, so the danger is low. However, I did have the spring compressor when I did it. Removing the rear spring w/ the compressor still requires removing the lower control arm at one side.

For MANY models the left and right subframe bushings are the same. However, there are some models where they are not. And some modesl have higher bump stops than others. I recommend calling your parts supplier with your VIN# ready & if they tell you one size fits all call somebody else. The origianl parts were solid rubber & the newer ones are hydraulic (oil filled). Be sure to lubricate the bushings either with the MB sliding fluid or spray them with as much silicon as they will take. Otherwise, they will NOT fit properly (in the front).

For the diff bushings, I used the pull/push tool without any problems. They are a very tight fit. Be sure to install them like the old ones came out. The parts L/R are the same, but the bushing itself is asymmetric - there is a relief on one side.

There could easily be terminology confusion here.

The subframe bushings are those that mount the subframe to the body. The differential sub frame bushings, mount the differential to the subframe.

The subframe bushings are no big deal. The differential subframe bushings require the puller, or as suggested, air chisel them out. If you air chisel them out, you will still need the puller to install them without destroying the sheet metal subframe.

Have a great day,

What exactly does the subframe bushing do? My car seems very unstable in slight wind...there seems to be much lateral (side to side) movement. I thought it might be my pushing/pulling links, but my mechanic said they are fine. It's also not just the rear end that does this, but the whole car.

Thanks,
Matt

Wind sensitivity is often alignment (toe-in).

Can also be too high tire pressure (> 36 psi) or incorrect amount of steering play.

Don't trust an indy to do the alignment, pay the dealer as they use the spreader bar and will do it right. Without the spreader, its very difficult for a regular tire shop to get it right.

Brian right-on from my experience. I took the '91 and '95 to the local "super" tire store. Great people but couldn't get the alignment right. Repeatedly something was wrong. Burned off the outer edges brand new RE950s on both cars.

They have the latest and greatest laser racks etc .... took them to the dealer, and the first time, right. BTW, if the dealer has an old Bosch optical rack, run to a dealer that has a modern rack. Insist they use the spreader bar.

Once the alignment is right, unless you hit something you shouldn't have to align it again.

That's my expereince.

Haasman

Yeah, I did have it aligned by my indie (who takes it to his tire supplier who does the alignment). He said it was the alignment, but it sure doesn't feel like it. It feels like the body of the car is separated from the wheels. If the car catches a gust of wind, it'll move laterally without moving the steering wheel. Then I go to move the steering wheel the opposite way of the car to correct, and it'll seem to catch and be overcorrected. This happens constantly with slight winds. Sound like alignment still?

Thanks.
Matt
94 e320

Yes. Your car should NOT be that sensitive to side winds. I'd bet your front toe-in is out of spec (too small). This will also lead to the oversteer conditions you are describing. For comparison purposes (not likely your problem) if it were the opposite, too much toe-in, you'd be very stable on the road, experience understeer, and feather your tires.

Have you ckecked the steering damper? Sometimes you get the same symptoms you are describing because of a worn out/failed damper.

So steering damper and/or alignment. Not any bushings? So what are the symptoms of bad subframe bushings?

Thanks,
Matt

As with any bushing, you push, prod and pry to see whether or not it is tight. If it is loose, it needs replacing.

Good luck,

The subframe mounts are collapse internally are are hard to spot. With the rear on jackstands at the jack points: The rear mount closest to the bumper, if the metal washer is recessing in towards the mount its seen better days. For the mounts towards the front of the car will stretch and show a lot of cracking. In extreme cases, the mount will be completely separated or torn. You will know that for sure driving the car. However, even if you replace them there is NO guarantee that it is the cause of your problem. If you have your indy to the alignment again, you will probably still have wind sensitivity. Same as if you replace your springs & shocks. If the toe-in ain't right, she's gonna blow all over the road. I have rebuilt every part of my suspension from the frame floor to the wheels. My best advise is to pay the dealer for an alignment. It will either fix your problem or elminate one possibility. Let us know how it turns out.

China Clipper,

Seems like a lot of good advice. It is going to be interesting to see what cured your car's problem. I think some of these items you can check out yourself which is good ($).

Additionally, while you are having the dealer do your alignment, you could pay say an extra 1/2 hour FIRST and have them check all the items we have all mentioned and suggested.

You may have a pleasant surprise ... or ..... at least you'll know and it will be BEFORE the alignment. After all, some items require an alignment and you wouldn't want to have to pay for it twice.

Keep us updated,

Haasman

Update
 

I had an alignment done a couple weeks (by my independent, not the dealer...), but my car is still moving too much laterally with any bit of wind. I think the wind makes the movement more obvious, but I can notice it a little at anytime.

My new alignment did make the car more stable...it was done to different specs this time. I guess Mercedes put out a service bulletin for alignment to compensate for cross wind, and that's what it's aligned to now. I am a little concerned about my 4 month old tires wearing out unevenly (feathering, perhaps), but since it was a Mercedes bulletin, I guess they won't.

I also had the 30k service done at the same time, and my mechanic looked over the car well for bushing wear and other worn suspension components, but they said it looks fine in those areas. The only thing I know that I need to replace are my motor mounts. Would collapsed motor mounts cause my front end to act "loose" and cause the car to move side-to-side? Would winds tend to blow the motor around just enough to cause the car to act this way? I can't tell if it acts worse on grooved pavement as opposed to a smooth road, but sometimes it seems to. I wonder if it could be some other suspension component?

Thanks,

Matt
94 E320
149.5k

Why don't you take it to the DEALER to see if your alignment is correct?

In my experience I can pay an indy today, tomorrow, and the next day and the alignment will never be correct!! You can change every part of the suspension or just the struts, but if its not aligned correctly, it will still more sensitive to winds that it should be.

Please see my other posts in this thread about toe-in & wind. IF it were my money I'd go to the dealer. If they don't find the alignment a problem, they may tell you something about worn parts your indy missed. I know people that use the Sac dealer for alignments with excellent results.

Cause I'm an idiot.

I had to have some other work done, and thought they could look at the problem, that maybe there was some suspension part broken and they could fix it cheaper. The car does ride much better, but not good. I guess I'll have go to the dealership, like I should have.

Matt

Correct alignment on the W124 REQUIRES that the front wheels be spread by a spring tool at the front while the alignment is being done. If not, the toe-in cannot be set correctly, and few shops do this other than the dealer or a VERY good tire store (they get to replace tires ruined by incorrect toe-in).

Have the alignment done again, after making sure the shop has the correct tools.

Incorrect toe-in will make the car blow all over the road, and "dart" from side to side in slippery conditions like the 280 SE is doing since I replace the upper control arm bushing.

Peter

wind sensitivity.......
 

I recently replaced the front sway bar bushings on our 190E with 105k mi. I did it only because of age and mileage, ease of the job, cheap parts, and I was under there replacing tranny mount and exhaust hangers anyway. Sort of 'padding' the parts bill to amortize shippng costs.

Wind sensitivity had been noticebly higher than I liked, and it immediately and unexpectedly improved after this repair. Note that the old bushings did not appear loose, but on removal, the holes were definitely larger than on the new ones.

I haven't tried driving yet with INTENSE crosswinds, but still any improvement is nice.

Steve